Concentration of ores.



1. LYSTER. CONCENTRATION OF ORES. APFLlCATlON FILED JULY 14, ISIS.

2 SHEETS-SHEET 1'. v

F. 1. LYSTER. CONCENTRATION OF ORES. 1 APPLICATION FIL'ED JULY I4, [915. 1,203,373. Patented Oct. 31,1916.

2 SHEETS-SHEET 2- UNITED STATES ATENT orricn.

FLEURY JAMES LYS'IER, OIE BROKEN HILL, NEWSOUTH WALES, AUSTRALIA, ASSIGNOR BY MESNE ASSIGNMENTS, 'IO MINERALS SEPARATION AMERICANSYNDICATE (1913) LIMITED, OF LONDON, ENGLAND.

CONCENTRATION. OF ORES.

1,203,373. Original application filed May 8, 1913, Serial Specification of Letters Patent.

Patented Oct. 31, 1916.

No. 766,346. Divided and this application filed July 14,1915.

Serial No. 39,927.

of Australia, have invented certain new and useful Improvements in the Concentration of'Ores, of which the following is a specification, reference being had therein to the ac .companying dra\vi ngs,forming part thereof= This invention relates to improvements in the concentration of ores and is particularly applicable to the separation of mixed zinc and lead sulfid .ores, and this application is a division of my application filed May 8, 1913, Serial No. 766,346.

The object of this invention is to separate metalliferous portions of an ore such, for example, as the sulfid of lead (galena) from other portions of the ore, and more particailarly to effect a differential or selective flotation in the treatment of mixed zinc and lead sulfid ores, to wit: the separation of lead sulfid galena) from zinc sulfid (blende), obtaining a product relatively rich in lead on the one hand, and a zinc product relatively low in lead on the other hand.

I have discovered that sulfid of lead (galena) may be separated from sulfid of Zinc (blende) without any preliminary treatment by subjecting the ore or metalliferous materials to a flotation separation treatment at a low temperature with encalyptus oil or other frothing agent and with agitation or aeration in an alkaline solution containing, for example carbonate of sodium.

The suitability of any given substance in an alkaline solution can be easily determined by a laboratory test as hereinafter described.

In carrying this process into effect a plant similar to that employed in and common to agitation froth processes may be employed.

I have shown in the accompanying drawings two forms of apparatus adapted for carrying out my process.

Figure 1 is a longitudinal elevation and Fig, 2 a cross-section of a unit with the supply devices in elevation, and Fig. 3 is a sectional elevation of an apparatus suitable for testing.

I will now describe my process as carried out in the apparatus shown in Figs. 1 and 2. The ore is first ground to a suitable degree of fineness (preferably to slimes so that the different metallic sulfid particles are disassociated from each other). This finely ground ore with its accompanying circuit water (which is a solution such as hereinbefore described) is led into a settler or thickener A to remove excess water. The thickened pulp is then led into a vessel B, from which it passes to the first centrifugal pump C of the series C C C (3*, C, C. These centrifu al pumps are each" connected to the individual members of a corresponding series of separating boxes D D D,

material treated, as wellas the requisite amount of air (such as by a tap F) into the suction pipe G thereof, which is connected to the feed vessel B. The centrifugal pump D, D, l K These centrifugal pumps act as C draws in pulp, air, and frothing agent, and produces an intimate mixture which is discharged through the outlet pipe H to the separator box D the delivery of the pump being controlled by the admission of air by the tap F. The particles of lead sulfid- (galena) are found to rise to the top of the separator box D where an inverted pyramid J diverts the froth toward the discharge lip or launder K from which it flows to the receptacle for settling and collecting the lead concentrate. The particles which domot rise or float, together with the balance of the water. sink to the bottom of 'the box D and are there withdrawn by the outlet pipe L which is connected to the suction pipe G of the next pump C of the series, and the operation is repeated, the residues of one separator box D passing to the centrifugal pump C of the next in series. In the plant illustrated in the accompanying drawings there are six separator boxes and their attendant pumps, which comprise one series or unit,-but it will be understood that this number is dependent upon the proportion of mineraleontained in the ore and the degree of agitation and aeration required, the repetition of the operations be-' .process is used with this ore for this purpose the solution should be only slightly alkaline, butsuflicient to respond to the well known methyl orange'test.

The suitability of the substances hereinbefore indicated and the proportion thereof to the solution and the degree and duration of agitation or aeration of the material treated can be determined in a laboratory test which may be conducted as follows in an apparatus such as is illustrated in Fig. 3 of the accompanying drawings: This apparatus comprises an agitating or mixing vessel N having a rotating impeller O, a separating box P on the side thereof con nected to the mixer by a passage R and by a flexible hose pipe S at the bottom. In carrying out a test the mixing vessel N con tains the solution which corresponds with theeircuit water of the working plant, and eucalyptus or other frothing agent is then added in measured quantities. The impeller O is then rotated at about 1700 revolutions per minute and a. charge of about ell-8 grammes of ore is fed in. Sufficient solution is added to fill the separating box P to the level of its discharge lip. The agitated pulp is forced through. the passage R into the separating box I and the float or froth rising to the surface is skimmed off over the lip. The pulp is continuously circulated by being drawn from the bottom of the box I by' the pipe S back into the mixer N by the action of the impeller O. The flotation is continued until the float or froth is noticed by observation to become lower in lead and the zinc begins to appear therein. The appearance of the concentrate being skinnned off over to the lip of the separating box will indicate the duration of agitation necessary to obtain a good concentrate combined with a good recovery, while experience will indicate the amount of frothing agent necessary, and farther quantities may be added at inter ads as found necessary. The residue is run off from the bottom of the machine by disconnecting the flexible hose or pipe S. Repeated trials with different solutions and with different strengths will indicate what is best suited to the particular ore under treatment. The ascertained duration of agitation and aeration will govern the number of separator boxes which will be necessary in the working plant when that hereinbefore described is used.

I have found that in obtaining a selective separation of the lead sulfids from the zinc sulfids in the ore heretofore referred to, known as calcitic slimes at Broken Hill, to which my process, is peculiarly. well suited, m'ei'aging about eleven per cent. (11%) of zinc and about thirteen per cent. (13%) of lead, and using about from two (2) to five (5) lbs. of eucalyptus per ton, I have ob tained good results with a solution of sodium carbonate in the proportion of 500 grains per'gallon. I have also obtained good results with a solution of sodium bicarbonate in the proportion of 600 grains per gallon.

In another modification of the above procedure I have used calcium chlorid, 300 grains per gallon, with calcium hydrate, 3.6

grains per gallon, and in anothernnodificm tion have used calcium nitrate, 300 grains per gallon, with calcium hydrate, 18 grains per gallon,

I have further discovered that the residues obtained as before described containing the bulk of the zinc sulfids may be further treated by flotation separation to produce a concentrate rich in zinc by first dewatering a nd thickening the pulp and then submitting it to a repetition of the flotation separation, using. however, sutlicient water in lieu ,of the solution previously employed, or by further continuing the process hereinbefore described, after the recovery of the lead sulfids galena) in a separate de-zincing unit until ,the zinc sulfids (blende) appear upon the surface of the solution and are carried over into the launder hereinbefore mentioned. In operation I prefer the former to the latter method for the recovery of the zinc sulfids (blende). In this way azinc concentrate may be obtained and thereby both the lead. sulfids and Zinc sulfids recovered in separate products by flotation separation without recourse to separation by gravitation or tables or vanners as heretofore.

claim A process of concentrating ores which consists in agitating and aerating an ore pulp containing in solution an alkaline selectivity-modifying agent and containing a small proportion of a frothing agent, so as to obtain a froth of concentrates, the solution being alkaline during separation and sepa rating the froth.

'2. A process of concentrating ores which consists in agitating and aerating an ore pulp containing in solution a salt of a mineral acid having an alkaline reaction and containing a small proportion of a frothing agent, so as to obtain a. froth of-co'ncen-' 'lrates, the solution being alkaline during separation and sepa 'atmg the froth.

3. A process of concentrating ores which consists in agitating and aerating-an ore pulp containing sodium carbonate in solution and containing a small proportionof a frothing agent, so-as to obtain a froth of fids (galena) from zinc sulfids (blende) in concentrates, the solution being alkaline during separation and separating the froth;

l. A process for the separation of lead sulfids (ga'lena) from zinc sulfids (blends) in ores containing mixed lead and zinc sulfids'whicli consists in subjecting the said ores I to the agitation froth process by agitating fids which consists in subjecting the said them witha frothing ag nt in an alkaline. solution, thereby separatingthe lead sulfids from the 'zinc'sulfids. A

5. Aprocess' for the-separation of lead sulfids (galena) from zinc sulfids (blende) in ores containing mixed lead and zinc sulores to the agitation froth process by agitating them with a frothing agent in an alkaline solution containing a compound of an alkaline'metal, thereby separating thefilead sulfids from the zinc sulfids. f j

6. A process for the separation of 'lead su'l' fids (galena) from zinc sulfids (blende)in ores containing mixed lead and zinc sulfids which consists in subjecting the said ores to the agitation froth process by agitating them with a frothing agent in an alkaline-solution containing sodium ca rbonate, 'thereby separating the lead sulfids from theizinc sulfids. a

7. A process for the separation of lead sul fids (galena) from zinc sulfids (blende) in ores containing mixed lead and zinc sulfids, which consists in subjecting the'said ores to the agitation froth process by agitating them with a frothing agent in an alka line solution, thereby obtaining .a concentrate relatively rich 1n lead, and in submit ting the residues to a dewateringand thickening operation and finally subjecting the same to a repetitionof the agitation froth process witlrfresh water inlieu of the solu- -tions previously employed,"thereby obtaining' a concentrate relatively rich in zinc.

' 8. .A process for the separation of lead sulfids (galena') from-z1nc sulfids (blende) in ores containing mixed lead and zinc sulfidswhich consists in subjecting the said ores to the agitation froth process by agitat ng them with a froth'ing agent in an alkaline solution containing a compound ofan alkaline metal, thereby obtaining a concentrate relatively rich in lead, and in submitting the residues to a dewatering and thickening op-' eration and finally sub ecting the same to a" repetition of the agitation froth process with fresh water in lieu of the solution previously employed, thereby obtaining a concentrate ,1'elatively rich in Zinc.

9. A process for theseparation of lead sulores containing mixed lead and zinc sulfids which consists in subjecting the said ores to y the agitationfroth processby agitating them with aifrothineg agent in an alkaline solution containing so ium carbonate, thereby obtaininga concentrate relatively richin lead, and in submitting the residues to a d'ewatering andthickening operationand finally subjecting the same to a repetition of the agi tation froth process with fresh water in lieu of the solutions previously employed, there-- \by obtaining a concentrate relatively rich in I zinc. a A a 10. A process for the separation of lead sulfids (galena) from zinc sulfids (blende) inores containing mixed'lead and zinc Sillfids by subjecting the saidores to-the agitation froth process by agitating them'with a froth-ing agent in an alkaline solution, thereby obtaining a concentrate relatively rich in lead and in submitting the residues to fur.-

ther agitation, thereby obtaining a concen-,

trate relatively rich in zinc.

1'1. Aiprocess for the separation of lead sulfids (galena) from zinc sulfids (blende) in ores containing 'mixed lead and zinc sul-l fids, by subjecting the s aidores to the agitation froth pro'cessby agitating them with a frothing agent in an alkaline solution containing a vcompound of an alkaline metal, thereby obtaining a concentrate relatively rich in lead and submitting the residues to further agitation, thereby obtaining alconcentrate relatively rich in zinc.

12, A process for the separation of lead sulfids '(galena) from zincsulfids (blende) in ores containing mixed lead and zinc sulfids, by subjecting the said-ores to the agitation froth process by agitating them with a .frothing agent in an alkaline solution containing sodium carbonate, thereby obtaining a concentrate relatively rich in lead and in submitting the residues to further agitation,

thereby obtaining a concentrate relatively rich in zinc.

In testimony whereof I have afiixed my signature in presence. of two witnesses.

FLEURY J AMESLY STER.

Witnesses:

ARTHUR GORE CoLLIsoN,

LESLIE HERBERT. BROADBENT. 

